1  /* Copyright (C) 1995,1996,1997,1998,1999,2002,2003
       2  	Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, write to the Free
      17     Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
      18     02111-1307 USA.  */
      19  
      20  #include <config.h>
      21  #include <float.h>
      22  #include <math.h>
      23  #include "../printf/gmp-impl.h"
      24  
      25  /* Convert a multi-precision integer of the needed number of bits (113 for
      26     long double) and an integral power of two to a `long double' in IEEE854
      27     quad-precision format.  */
      28  
      29  __float128
      30  mpn_construct_float128 (mp_srcptr frac_ptr, int expt, int sign)
      31  {
      32    ieee854_float128 u;
      33  
      34    u.ieee.negative = sign;
      35    u.ieee.exponent = expt + IEEE854_FLOAT128_BIAS;
      36  #if BITS_PER_MP_LIMB == 32
      37    u.ieee.mantissa3 = frac_ptr[0];
      38    u.ieee.mantissa2 = frac_ptr[1];
      39    u.ieee.mantissa1 = frac_ptr[2];
      40    u.ieee.mantissa0 = frac_ptr[3] & (((mp_limb_t) 1
      41  				     << (FLT128_MANT_DIG - 96)) - 1);
      42  #elif BITS_PER_MP_LIMB == 64
      43    u.ieee.mantissa3 = frac_ptr[0] & (((mp_limb_t) 1 << 32) - 1);
      44    u.ieee.mantissa2 = frac_ptr[0] >> 32;
      45    u.ieee.mantissa1 = frac_ptr[1] & (((mp_limb_t) 1 << 32) - 1);
      46    u.ieee.mantissa0 = (frac_ptr[1] >> 32) & (((mp_limb_t) 1
      47  					     << (FLT128_MANT_DIG - 96)) - 1);
      48  #else
      49    #error "mp_limb size " BITS_PER_MP_LIMB "not accounted for"
      50  #endif
      51  
      52    return u.value;
      53  }